Prince RV Series Differential Poppet Line Relief Valve: NO. RV-5L30, 30 GPM, 500-1500 PSI Relief and Max Upto 3000 PSI With #8 SAE Port Size Prince Differential Poppet Inline Relief Valves (RV Series) Port Size: SAE 8 PSI: 500-1500 Relief Setting: 1000 PSI GPM Flow: 30